Acid wash help

[surfref32]

I didn't see a category where this thread should go so mods please move it to its rightful place. Anyway, we had our pool installed exactly 10 years ago. 15x30' 17k gal. concrete with a Florida Stucco Gem finish. I've been doing the BBB method from day one with success. Two years ago we had way too much rain (alkaline) and I allowed my PH to rise a bit too high and some iron staining occurred. It was mainly just some darker areas. Last Summer I tried the ascorbic acid treatment as detailed on TFP. I ended up with clean splotches all over. (see attached pic taken today) That issue was minor and on the back burner. A couple of weeks ago when the CL shortage hit, I decided to make the switch to SWCG. I ordered the salt test kit but before it came in I thought I'd be safe adding 66% of what the chart said. I thought wrong and I ended up with 5600 ppm salt. I calculated a 28% drain and refill to get the salt right and started that this morning but thought this would be the perfect time to acid clean especially when our ground water levels are at a record low. It has never been cleaned. So, all that said, is muriatic acid safe for the Gem finish and if so at what concentration? Thanks for reading!

 

[zea3]

I would not do an acid wash on 10 year old plaster. What are your current test results? Are there areas that are rough to the touch? I'll ask a couple of experts to give an opinion.
@JamesW @jimmythegreek @bdavis466

 

[JamesW]

I would do a sulfamic acid treatment with Jack's copper and scale stuff and then do a drain and refill if it's safe to do the drain without floating the pool.

 

[surfref32]

I would not do an acid wash on 10 year old plaster. What are your current test results? Are there areas that are rough to the touch? I'll ask a couple of experts to give an opinion.
@JamesW @jimmythegreek @bdavis466

Is my pool surface plaster? (pic attached) I don't see any areas that are rough to the touch. To me, the surface looks like it did when it was new. There are just some areas that are darker than they should be. The ascorbic acid worked just fine, it just didn't spread evenly across the surface, hense the splotches.(pic in post 1) The chemistry was near perfect except for the salt. FC=5, PH=7.5, CYA=45, TA=100, CH=300

I would do a sulfamic acid treatment with Jack's copper and scale stuff and then do a drain and refill if it's safe to do the drain without floating the pool.

I really need to get this done tomorrow. I'm not sure if I can get the Jack's product. Yesterday I called the contractor that installed the pool to ask about a price for cleaning it and if he couldn't, I was going to ask him what product to use. I called twice, no answer and no returned calls. This morning I called two other pool contractors that had great reviews. No answer, no returned call. At lunch I called Florida Stucco, the people that made the product that's on the pool walls, to ask for cleaning instructions. They answered but said a field rep would call me back. No luck there either so I'm hoping I can figure this out online tonight.

 

[zea3]

Any pool surface that is trowled on with a masonry base, whether or not it contains pebbles, is referred to as a plaster surface for purposes of determining pool chemistry. An acid wash traditionally referres to using high amounts of muriatic acid to remove a microscopic layer of masonry finish to expose "fresh" plaster, which also shortens the life of your pool finish. Think of it as a chemical peel for your pool. When you did an ascorbic acid treatment, you did not remove a layer of the pool's finish. You initiated a chemical reaction that released the iron deposits from the surface of the pool and put it back into solution (suspended the iron particles back into the water). The average life of a masonry surface is about 10 years. Your pool is currently 10 years old, so an acid wash could potentially cause serious damage to your pool surface. Also an acid wash is done with a full pool. Were you planning to scrub or power wash the pool while empty with a muriatic acid solution?

 

[surfref32]

Any pool surface that is trowled on with a masonry base, whether or not it contains pebbles, is referred to as a plaster surface for purposes of determining pool chemistry. An acid wash traditionally referres to using high amounts of muriatic acid to remove a microscopic layer of masonry finish to expose "fresh" plaster, which also shortens the life of your pool finish. Think of it as a chemical peel for your pool. When you did an ascorbic acid treatment, you did not remove a layer of the pool's finish. You initiated a chemical reaction that released the iron deposits from the surface of the pool and put it back into solution (suspended the iron particles back into the water). The average life of a masonry surface is about 10 years. Your pool is currently 10 years old, so an acid wash could potentially cause serious damage to your pool surface. Also an acid wash is done with a full pool. Were you planning to scrub or power wash the pool while empty with a muriatic acid solution?

Thank you for your replies. I now understand the term plaster. Yes, I feel this is the best time to drain and clean the pool surface. I found the procedure online last night here Pool Acid Washing | In The Swim I know nothing of a full pool acid wash. I just want to make the pool look new again. I thought my only option was the drain and clean. What are my options?